[Prevalence of infection and risk factors among family members in Qinghai Province, China].

To investigate the prevalence of infection among family members, and analyze associated risk factors. The current investigation was a cross-sectional study. The Qinghai region was stratified into urban areas, agricultural areas, and pastoral areas. The urban areas of Xining City, the agricultural areas of Haidong City, and the pastoral areas of Haibei Tibetan Autonomous Prefecture were selected. A total of 396 resident families (1 131 people) who underwent health checkups from 2021 to 2022 in the above areas were included in the survey study. Questionnaires were administered and infection was detected using the C-urea breath test. Numerical data were expressed as cases and percentages, and the Chi-square test was used to compare differences in infection rates in the populations and families in each group. Multifactorial logistic regression was used to analyze risk factors for infection, and 0.05 was considered statistically significant. The prevalence of infection in Qinghai province was 52.8% (597/1 131) and the prevalence of infection in households was 80.6% (319/396). In -positive households with at least 1 infected spouse, 40.4% (36/89) had only 1 infected spouse, and in 59.6% (53/89) both spouses were infected. In analysis of children infected by parents with , 20.0% (9/45) of households had fathers and children infected, 48.9% (22/45) had mothers and children infected, and 31.1% (14/45) had both parents and children infected. In univariate analysis there was a statistically significant difference in the overall comparison of infection rates among families with different numbers of people living together (=11.12, =0.004), and between-group comparisons suggested that infection rates were higher in families with 4 or 5 people and more than 5 people living together than in families with 2 or 3 people living together. The infection rate was higher in families that did not use serving chopsticks and spoons during family meals than in families that did use serving chopsticks and spoons (=6.12, =0.013). In multifactorial logistic regression analyses the number of people living together in a family and whether or not serving chopsticks and spoons were used at family meals were associated with infection (<0.05). The infection rate in families in Qinghai Province is high, and there is a clear association with family aggregation. It is more common for both members of a couple to be infected, and infection of a mother has a greater effect on the children's infection status than infection of a father. The infection rate of was lower in families that used serving chopsticks and spoons during dinner gatherings, and the fewer the number of people living together in the family, the lower the infection rate.